Struct UndoHistory 

pub struct UndoHistory { /* private fields */ }

One field’s undo history: what it was, and what it was about to be.

Implementations

impl UndoHistory

pub fn record(&mut self, before: EditSnapshot, kind: EditKind, since: f32)

Records that the field, which was before, has just been changed by a change of kind kind, since seconds after the last one.

A change that joins the run in progress records nothing: the run’s first entry already holds the state the whole run will be undone to.

pub fn close_run(&mut self)

Ends the run in progress without recording anything: the caret moved, so what is typed next is a step of its own.

pub fn undo(&mut self, current: EditSnapshot) -> Option<EditSnapshot>

Steps back: current is where the field is now, and the answer is where it should go. None when there is nothing to undo.

pub fn redo(&mut self, current: EditSnapshot) -> Option<EditSnapshot>

Steps forward again, undoing an undo. None when nothing was undone.

pub fn can_undo(&self) -> bool

Whether there is a step to go back to.

pub fn can_redo(&self) -> bool

Whether there is a step to go forward to.

Trait Implementations

impl Clone for UndoHistory

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for UndoHistory

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for UndoHistory

fn default() -> Self

Returns the “default value” for a type.

impl Eq for UndoHistory

impl PartialEq for UndoHistory

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for UndoHistory